Geology and Mineralogy. 469 



and chemistry of arid soils, a natural result of the author's long- 

 experience in the arid west. The book is further characterized 

 by its strong treatment of the effect of soil character upon native 

 vegetation, for the value of which the author has been contend- 

 ing for half a century. The fundamental question of classifica- 

 tion as involving the relative value of physical and chemical 

 properties in plant production and as a convenient means of ref- 

 erence to cultural values, is discussed in a thoroughly convincing 

 manner. In view of the recent discussions on the relation of 

 soil texture and chemical constitution to the composition of the 

 soil-water, Hilgard's conclusions are of the highest interest and 

 value, and strongly contravene the assertion that natural solu- 

 tions of water-soluble soil ingredients are essentially of the same 

 composition in all soils. A commendable feature of the soil 

 analyses is their statement in terms which insure application. 

 They really constitute a sort of restatement of refined analyses 

 such as give the conclusions an immediate and practical value to 

 the agriculturist. i. b. 



9. Brief Notices of some recently described Minerals. — 

 Kleintte is an oxychloride of mercury described by A. Sachs 

 from Terlingua, Texas, and named after Prof. Carl Klein of 

 Berlin. It occurs in slender hexagonal crystals of a sulphur-yel- 

 low to orange color ; hardness 3-4 ; specific gravity = 7*441. 

 The composition deduced is H 4 C1 2 3 . Sachs regards this mineral 

 as identical with one noted by Moses (" No. 5," this Journal, xvi, 

 263) and also with that announced by Hillebrand (Ibid., xxi, 85). 

 — Sitzungsber. Akad. Berlin, Dec. 21, 1905 ; Central. Min., 200, 

 1906. 



Bellite is a chromo-arsenate of lead from the Magnet Silver 

 mine, Magnet, Tasmania ; it is named after Mr. W. R. Bell by 

 W. F. Petterd. It occurs in delicate tufts and velvety coatings 

 lining cavities in a soft iron-manganese-gossan ; minute hexagonal 

 crystals are sometimes visible. The color is bright crimson to 

 orange-yellow; hardness 2*5 ; specific gravity 5*5. An analysis 

 by J. D. Millen gave : 



As 2 3 Cr0 3 PbO P 2 5 V 2 5 A1 2 3 S0 3 CI Si0 3 



6-55 22-61 61-68 0-04 0-11 0-01 0-05 0*52 7 -59 = 99'16 



Giorgiosite is a name given by Lacroix to a basic hydrated 

 magnesium carbonate forming a white powder with sodium 

 chloride and other salts at the fumaroles of Santorin at the erup- 

 tion of 1866. The powder consists of minute radiated spherules. 

 This is inferred to be identical in composition with a salt de- 

 scribed by Fritzsche having the formula 4MgC0 3 .Mg(OH) 2 .4H 2 0. 

 Another associated substance in white flocculent masses is prob- 

 ably hydromagnesite. — Bull. Soc. Min., xxviii, 198. 



Silicomagnesioeluorite, as its name expresses, is essentially 

 a fluosilicate of magnesium. It is described by P. Zemiattschen- 

 ski from Lupikko, Finland. It occurs in crystalline aggregates 

 of half-spherical or spherical forms with radiated and fibrous 



